Prior art consists of graphite or fine wire brushes that rub against conductive rings that in turn, pass electricity across a rotating device. Other methods use a thin wall metal ring (or rings) that is lightly compressed into an ellipse that conducts between two concentric rings. When multiple rings are used, they would require a means of separation that is accomplished by way of planetary gears that act as separators or plastic spacers placed between each conducting ring.
The disadvantages of prior art are many. Graphite or thin wire brushes are a source of electrical noise that is detrimental when used to pass signal. Additionally, these methods generate wear and particles that further degrades the performance of the conductive path. These devices are prone to produce sparks that can also degrade their performance and become hazardous if employed in volatile environments or areas where combustibles are stored. Although thin wall metal ring devices produce less noise, wear and spark potential, they cannot be made to provide a large contact area that is important in applications where large amounts of current is needed to be conducted across a rotating device. Furthermore, it is inherently difficult to introduce multiple rings in an effort to increase the current carrying capacity of the electrical path without the introduction of spacer materials that will in turn, rub against the rings or other separation components causing particle generation.